It appears that most folks who post on this forum routinely 'recap' any old radio they are restoring. What is the philosophy behind this? Do you routinely replace ALL paper capacitors? Or are you a bit more conservative?

I routinely replace electrolytic capacitors on anything that has not been 'playing' for ten years or more, and always on an older radio. I do not routinely replace all paper capacitors; it depends on where the capacitor is in the circuit, its manufacturer, and how the radio has been stored. Plate to grid coupling capacitors are always replaced, as a failure can take out a tube and an output transformer. I typically replace the capacitor(s) from output tube plate(s) to B+ or ground, anything across all or part of the AC line, and anything that has 'oozed out' its wax. I check manufacturer, how conservative the rating is, and physical appearance on everything else, and frequently replace capacitors in the AVC circuit, as these operate in a circuit with high resistances. I typically do not replace paper screen and cathode bypass capacitors, nor other 'paper' bypass and filter capacitors. Sometimes I measure a few to get an idea of the overall condition of the radio, and find that the leakage resistance is greater than 20 megohms.

I keep an old radio on my desk at work at all times, with or without case, play it all day, and swap out periodically. I have never had a capacitor failure. There is a certain allure in the appearance of old capacitors. When I replace a capacitor, paper or electrolytic, I sometimes put the new unit inside the old case.

Anything with electrolytic capacitors in it needs to be operated periodically, as even new units develop elecrical leakage if allowed to sit idle for years.

I welcome comments, and appreciate everything that is posted on this forum.

Many thanks,
Ed M

:It appears that most folks who post on this forum routinely 'recap' any old radio they are restoring. What is the philosophy behind this? Do you routinely replace ALL paper capacitors? Or are you a bit more conservative?
:
:I routinely replace electrolytic capacitors on anything that has not been 'playing' for ten years or more, and always on an older radio. I do not routinely replace all paper capacitors; it depends on where the capacitor is in the circuit, its manufacturer, and how the radio has been stored. Plate to grid coupling capacitors are always replaced, as a failure can take out a tube and an output transformer. I typically replace the capacitor(s) from output tube plate(s) to B+ or ground, anything across all or part of the AC line, and anything that has 'oozed out' its wax. I check manufacturer, how conservative the rating is, and physical appearance on everything else, and frequently replace capacitors in the AVC circuit, as these operate in a circuit with high resistances. I typically do not replace paper screen and cathode bypass capacitors, nor other 'paper' bypass and filter capacitors. Sometimes I measure a few to get an idea of the overall condition of the radio, and find that the leakage resistance is greater than 20 megohms.
:
:I keep an old radio on my desk at work at all times, with or without case, play it all day, and swap out periodically. I have never had a capacitor failure. There is a certain allure in the appearance of old capacitors. When I replace a capacitor, paper or electrolytic, I sometimes put the new unit inside the old case.
:
:Anything with electrolytic capacitors in it needs to be operated periodically, as even new units develop elecrical leakage if allowed to sit idle for years.
:
:I welcome comments, and appreciate everything that is posted on this forum.
:
:Many thanks,
:Ed M
:
Jon

It's a matter of dependability. Capacitors are cheap, and easy piece of mind to insure reliability. Long Life.

:It's a matter of dependability. Capacitors are cheap, and easy piece of mind to insure reliability. Long Life.
:
To me, a cap is something that has failed or, someday, is going to. So with an old radio, I change as many as I can get to, especially those in the high Voltage circuits, where most of the electrolytics live. Some people re-form old electrolytics and keep them in the radio if they work, to me that is like restoring an old car and putting used tires oon it.
Lewis

EdM,
I agree up to a point, ie "if it ain't broke don't fix it", but without life-cycle data on 70 year old components, its hard to predict their remaining life. The technology of yesteryear was built on integrity of the mfr, and worked for decades, but the bottom line and our throw-away society became involved to the detriment of modern mfg'g techniques. If you're gonna play it in your living room and it breaks, go fix it again, but if it's sold, the buyer may want a warranty. I started my restorations (2002) with the same thoughts in mind, but soon discovered my reputation was at risk if a restoration failed because of a 70 year old cap. I'm not a collector, so replacing all the old dryed out paper/wax caps is a given, when my reputation is at stake. Putting new components inside old containers is fun, messy, time consuming and makes an NOS set look its age, but few take the opportunity to remove the chassis to inspect the myriad of components for authenticity. You would probably replace a tube if it tested marginal

marv

:It appears that most folks who post on this forum routinely 'recap' any old radio they are restoring. What is the philosophy behind this? Do you routinely replace ALL paper capacitors? Or are you a bit more conservative?
:
:I routinely replace electrolytic capacitors on anything that has not been 'playing' for ten years or more, and always on an older radio. I do not routinely replace all paper capacitors; it depends on where the capacitor is in the circuit, its manufacturer, and how the radio has been stored. Plate to grid coupling capacitors are always replaced, as a failure can take out a tube and an output transformer. I typically replace the capacitor(s) from output tube plate(s) to B+ or ground, anything across all or part of the AC line, and anything that has 'oozed out' its wax. I check manufacturer, how conservative the rating is, and physical appearance on everything else, and frequently replace capacitors in the AVC circuit, as these operate in a circuit with high resistances. I typically do not replace paper screen and cathode bypass capacitors, nor other 'paper' bypass and filter capacitors. Sometimes I measure a few to get an idea of the overall condition of the radio, and find that the leakage resistance is greater than 20 megohms.
:
:I keep an old radio on my desk at work at all times, with or without case, play it all day, and swap out periodically. I have never had a capacitor failure. There is a certain allure in the appearance of old capacitors. When I replace a capacitor, paper or electrolytic, I sometimes put the new unit inside the old case.
:
:Anything with electrolytic capacitors in it needs to be operated periodically, as even new units develop elecrical leakage if allowed to sit idle for years.
:
:I welcome comments, and appreciate everything that is posted on this forum.
:
:Many thanks,
:Ed M
:

Even if it hasn't failed yet, I'm amazed at the amount of value drift on some of these old caps and resistors. Sometimes in the order of twice or three times or more from their intended value. Like a 100K resistor that measures 25 meg. All 'out of tolerance' or critical-duty (fire hazard) components get tested and replaced.
The peace of mind, lack of hum and improvement in sensitivity/fidelity is a pleasure to the ears.

:It appears that most folks who post on this forum routinely 'recap' any old radio they are restoring. What is the philosophy behind this? Do you routinely replace ALL paper capacitors? Or are you a bit more conservative?
:
:I routinely replace electrolytic capacitors on anything that has not been 'playing' for ten years or more, and always on an older radio. I do not routinely replace all paper capacitors; it depends on where the capacitor is in the circuit, its manufacturer, and how the radio has been stored. Plate to grid coupling capacitors are always replaced, as a failure can take out a tube and an output transformer. I typically replace the capacitor(s) from output tube plate(s) to B+ or ground, anything across all or part of the AC line, and anything that has 'oozed out' its wax. I check manufacturer, how conservative the rating is, and physical appearance on everything else, and frequently replace capacitors in the AVC circuit, as these operate in a circuit with high resistances. I typically do not replace paper screen and cathode bypass capacitors, nor other 'paper' bypass and filter capacitors. Sometimes I measure a few to get an idea of the overall condition of the radio, and find that the leakage resistance is greater than 20 megohms.
:
:I keep an old radio on my desk at work at all times, with or without case, play it all day, and swap out periodically. I have never had a capacitor failure. There is a certain allure in the appearance of old capacitors. When I replace a capacitor, paper or electrolytic, I sometimes put the new unit inside the old case.
:
:Anything with electrolytic capacitors in it needs to be operated periodically, as even new units develop elecrical leakage if allowed to sit idle for years.
:
:I welcome comments, and appreciate everything that is posted on this forum.
:
:Many thanks,
:Ed M
:

::It appears that most folks who post on this forum routinely 'recap' any old radio they are restoring. What is the philosophy behind this? Do you routinely replace ALL paper capacitors? Or are you a bit more conservative?
::
::I routinely replace electrolytic capacitors on anything that has not been 'playing' for ten years or more, and always on an older radio. I do not routinely replace all paper capacitors; it depends on where the capacitor is in the circuit, its manufacturer, and how the radio has been stored. Plate to grid coupling capacitors are always replaced, as a failure can take out a tube and an output transformer. I typically replace the capacitor(s) from output tube plate(s) to B+ or ground, anything across all or part of the AC line, and anything that has 'oozed out' its wax. I check manufacturer, how conservative the rating is, and physical appearance on everything else, and frequently replace capacitors in the AVC circuit, as these operate in a circuit with high resistances. I typically do not replace paper screen and cathode bypass capacitors, nor other 'paper' bypass and filter capacitors. Sometimes I measure a few to get an idea of the overall condition of the radio, and find that the leakage resistance is greater than 20 megohms.
::
::I keep an old radio on my desk at work at all times, with or without case, play it all day, and swap out periodically. I have never had a capacitor failure. There is a certain allure in the appearance of old capacitors. When I replace a capacitor, paper or electrolytic, I sometimes put the new unit inside the old case.
::
::Anything with electrolytic capacitors in it needs to be operated periodically, as even new units develop elecrical leakage if allowed to sit idle for years.
::
::I welcome comments, and appreciate everything that is posted on this forum.
::
::Many thanks,
::Ed M
::
: